I am getting the following error when trying to add the RCall package. Got the same error when I tried installing Feather before RCall. I don’t understand what is wrong. Would appreciate if someone can help.
Thank you.
Stacktrace
Pkg.add("RCall")
Resolving package versions...
ERROR: MethodError: Cannot `convert` an object of type Nothing to an object of type String
Closest candidates are:
convert(::Type{T<:AbstractString}, ::T<:AbstractString) where T<:AbstractString at strings/basic.jl:208
convert(::Type{T<:AbstractString}, ::AbstractString) where T<:AbstractString at strings/basic.jl:209
convert(::Type{T}, ::T) where T at essentials.jl:167
Stacktrace:
[1] setindex!(::Dict{Base.UUID,String}, ::Nothing, ::Base.UUID) at /Applications/JuliaPro-1.2.0-1.app/Contents/Resources/julia/Contents/Resources/julia/lib/julia/sys.dylib:?
[2] deps_graph(::Pkg.Types.Context, ::Dict{Base.UUID,String}, ::Dict{Base.UUID,Pkg.Types.VersionSpec}, ::Dict{Base.UUID,Pkg.Types.Fixed}) at /Applications/JuliaPro-1.2.0-1.app/Contents/Resources/julia/Contents/Resources/julia/lib/julia/sys.dylib:?
[3] resolve_versions!(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}, ::Nothing) at /Applications/JuliaPro-1.2.0-1.app/Contents/Resources/julia/Contents/Resources/julia/lib/julia/sys.dylib:?
[4] #add_or_develop#63(::Array{Base.UUID,1}, ::Symbol, ::typeof(Pkg.Operations.add_or_develop), ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at /Applications/JuliaPro-1.2.0-1.app/Contents/Resources/julia/Contents/Resources/julia/lib/julia/sys.dylib:?
[5] #add_or_develop#17(::Symbol, ::Bool, ::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::typeof(Pkg.API.add_or_develop), ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at /Applications/JuliaPro-1.2.0-1.app/Contents/Resources/julia/Contents/Resources/julia/lib/julia/sys.dylib:?
[6] #add_or_develop#12(::Base.Iterators.Pairs{Symbol,Symbol,Tuple{Symbol},NamedTuple{(:mode,),Tuple{Symbol}}}, ::typeof(Pkg.API.add_or_develop), ::String) at /Applications/JuliaPro-1.2.0-1.app/Contents/Resources/julia/Contents/Resources/julia/lib/julia/sys.dylib:?
[7] add(::String) at /Applications/JuliaPro-1.2.0-1.app/Contents/Resources/julia/Contents/Resources/julia/lib/julia/sys.dylib:?
[8] top-level scope at REPL[3]:1